Scope at let to a if statement

Since let creates a block scope, you need to create another block around it to limit its scope.

A block statement is used to group zero or more statements. The block is delimited by a pair of curly brackets.

let x = 1;
{
  let x = 2;
}
console.log(x); // logs 1

Alternatively you can use an Immediately Invoked Function Expression:

(function () {
    let entry = 6;

    if (entry) {
        console.log(entry);
    }
 })()
// Variable entry is not accessible from the outside scope

This is probably an idiom that was never made for JS, but just for kicks, here's a helper that could be used, although the other answer is probably more correct.

This was inspired by Clojure's when-let that does exactly what you're looking for, but doesn't require a function since it's a macro:

function ifDo (maybeTrueVal, doF) {
    if (maybeTrueVal) {
        doF(maybeTrueVal);
    }
}

ifDo(entries.find(....), (truthyVal) => {
    console.log(truthyVal);
});